Institut für Raumbezogene Informations- und Messtechnik
Hochschule Mainz - University of Applied Sciences

Optical Technologies

The term "Optical Technologies" covers a wide range of concepts and applications which use the properties of electromagnetisc radiation and today take part in nearly any area of everyday life, research and production.

Main competences of our institute in this field relay to digital imagery and camera technologies. We use cameras for precise measurements. Combined with algorithms it is possible to identify elements within images for a later localisation and use for varying mathematical models in relation to surveying needs.

Our existing skills include the treatment and mathematical description of cameras and precision measurments, the development of suitable algorithms for processing images and the mathematical modeling of surveying. Typical fields of applications are in industrial quality control, but also in medicine, metrology or spatial humanities.

Contact Person

Prof. Dr.-Ing. Frank Boochs

Tel.: +49 6131-628-1432
Fax.: +49 6131-628-91432

Prof. Dr.-Ing. Martin SchlĂĽter

Tel.: +49 6131-628-1440
Fax.: +49 6131-628-91440

Projects

Mit tachymetrischem 3D-Scanning im Verbund mit Structure from Motion Techniken zu georeferenzierten Punktwolken von schwer zugänglichen Objekten.
Optimierte geometrisch/physikalische Modellierung digitaler Industriemesskameras im Einsatz der industriellen Qualitätskontrolle.

Publications

COSCH - Vier Jahre interdisziplinärer Dialog zum Nutzen des kulturellen Erbes.

2017

RTF

KulturBetrieb - Magazin für innovative und wirtschaftliche Lösungen in Museen, Bibliotheken und Archiven








How to optimally record cultural heritage objects? Decision support through connected knowledge.

2017

RTF

EVA Berlin 2017. Elektronische Medien & Kunst, Kultur und Historie 24. Berliner Veranstaltung der internationalen EVA-Serie Electronic Media and Visual Arts, 2017

Optical recording of material cultural heritage (CH) is a multidisciplinary activity where the understanding of cross-disciplinary semantics is vital for a successful completion. In many cases, a lack of understanding of transdisciplinary semantics slows this process down. The end users who are mostly humanities experts lack the technical knowledge of spatial and spectral recording and could therefore demand more than what is actually required or sufficient for the intended CH application. The negotiations between technical experts and the end users are a tedious process. We present a semantic-based decision support system, COSCHKR, that employs reasoning and recommends optimal recording technology(ies) according to the application requirements of the recorded and processed data. COSCHKR is an ontology-based knowledge model that implies the development of semantic technologies within the Semantic Web framework. It represents formalized knowledge of the disciplines involved in the process of optical recording of material CH. The paper describes the applicability of the model in spatial, spectral, and visualization applications and summarises current possibilities and challenges.


Technical study of Germolles’ wall paintings: the input of imaging technique

2016

RTF

Virtual Archaeology Review

The Château de Germolles is one of the rare palaces in France dating from the 14 th century. The noble floor is decorated with wall paintings that are a unique example of courtly love spirit that infused the princely courts of the time. After being concealed sometime in the 19 th century, the paintings were rediscovered and uncovered in the middle of the 20 th century and partly restored at the end of the 1990s. No scientific documentation accompanied these interventions and important questions, such as the level of authenticity of the mural decorations and the original painting technique(s) used in the medieval times remained unanswered. The combined scientific and financial supports of COSCH COST Action and DRAC-Burgundy enabled to study Germolles' wall paintings using some of the most innovative imaging and analytical techniques and to address some of the questions raised. The study provided significant information on the material used in the medieval times and on the conservation condition of the paintings. The data collected is vast and varied and exposed the owners of the property to the challenges of data management.


Development of a platform recommending 3D and spectral digitisation strategies.

2016

RTF

Virtual Archaeology Review

Spatial and spectral recording of cultural heritage objects is a complex task including data acquisition, processing and analysis involving different technical disciplines. Additionally, the development of a suitable digitisation strategy satisfying the expectations of the humanities experts needs an interdisciplinary dialogue often suffering from misunderstanding and knowledge gaps on both the technical and humanities sides. Through a concerted discussion, experts from the cultural heritage and technical domains currently develop a so-called COSCH KR (Colour and Space in Cultural Heritage Knowledge Representation) platform that will give recommendations for spatial and spectral recording strategies adapted to the needs of the cultural heritage application. The platform will make use of an ontology through which the relevant parameters of the different domains involved in the recording, processing, analysis, and dissemination of cultural heritage objects are hierarchically structured and related through rule-based dependencies. Background and basis for this ontology is the fact that a deterministic relation exists between (1) the requirements of a cultural heritage application on spatial, spectral, as well as visual digital information of a cultural heritage object which itself has concrete physical characteristics and (2) the technical possibilities of the spectral and spatial recording devices. Through a case study which deals with the deformation analysis of wooden samples of cultural heritage artefacts, this deterministic relationship is illustrated explaining the overall structure and development of the ontology. The aim of the COSCH KR platform is to support cultural heritage experts finding the best suitable recording strategy for their often unique physical cultural heritage object and research question. The platform will support them and will make them aware of the relevant parameters and limitations of the recording strategy with respect to the characteristics of the cultural heritage object, external influences, application, recording devices, and data.


Knowledge guided object detection and identification in 3D point clouds

2015

RTF

Videometrics, Range Imaging, and Applications XIII, 952804

Modern instruments like laser scanner and 3D cameras or image based techniques like structure from motion produce huge point clouds as base for further object analysis. This has considerably changed the way of data compilation away from selective manually guided processes towards automatic and computer supported strategies. However it’s still a long way to achieve the quality and robustness of manual processes as data sets are mostly very complex. Looking at existing strategies 3D data processing for object detections and reconstruction rely heavily on either data driven or model driven approaches. These approaches come with their limitation on depending highly on the nature of data and inability to handle any deviation. Furthermore, the lack of capabilities to integrate other data or information in between the processing steps further exposes their limitations. This restricts the approaches to be executed with strict predefined strategy and does not allow deviations when and if new unexpected situations arise. We propose a solution that induces intelligence in the processing activities through the usage of semantics. The solution binds the objects along with other related knowledge domains to the numerical processing to facilitate the detection of geometries and then uses experts’ inference rules to annotate them. The solution was tested within the prototypical application of the research project “Wissensbasierte Detektion von Objekten in Punktwolken für Anwendungen im Ingenieurbereich (WiDOP)”. The flexibility of the solution is demonstrated through two entirely different USE Case scenarios: Deutsche Bahn (German Railway System) for the outdoor scenarios and Fraport (Frankfort Airport) for the indoor scenarios. Apart from the difference in their environments, they provide different conditions, which the solution needs to consider. While locations of the objects in Fraport were previously known, that of DB were not known at the beginning. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.


Netzmessungen mit dem Leica Absolute Tracker AT402 zur Bestimmung geodätischer Prüfstrecken

2015

RTF

Allgemeine Vermessungs-Nachrichten (avn)

Zur Bestimmung geodätischer Prüfstrecken unter Nutzung eines Leica Absolute Trackers AT402 stellen wir Konzept und Ergebnisse vor. Dazu greifen wir die positiven Erfahrungen mit Lasertrackern beim Ringversuch auf der neuen Kalibrierbasis der Universität der Bundeswehr München zwischen 2009 und 2011 auf.
Im Unterschied zum Ringversuch konzentrieren wir uns auf die Bestimmung neuer und bestehender PrĂĽfstrecken im derzeit ĂĽblichen Pfeilerdesign mit einer Pfeilerkopf-Abschlussplatte mit 5/8-Zoll-Gewindezapfen zur DreifuĂźaufnahme. DafĂĽr schlagen wir eine Netzmessung unter Verwendung einfacher Pfeiler-Aufsatzadapter vor. AbschlieĂźend vergleichen wir unsere Ergebnisse, die bei unterschiedlichen meteorologischen
Bedingungen auf der Eichstrecke Weinolsheim des Landes Rheinland-Pfalz gewonnen wurden.


Modulare Digitalkameratachymeter

2015

RTF

ns

Das Vorhaben will einen Innovationsschub fĂĽr die Anwendung vermessungstechnischer
Tachymeter (auch Totalstationen, mobile Polarmesssysteme groĂźer Reichweite)
auslösen.
Ermöglicht wird dieser Innovationsschub durch die Integration bildgebender Sensoren
mit einem konsequent modularen Lösungsansatz an Stelle der bislang mit nur
mäßigem Erfolg unternommenen monolithischen Lösungsansätze. Durch unser Konzept
werden die stark unterschiedlichen Entwicklungszyklen der zentralen Systemkomponenten
entkoppelt. Dadurch werden mittelfristig insbesondere KMU, Entwicklungseinrichtungen
und Hochschulen in die Lage versetzt, anwendungsspezifische
Lösungen für den expandierenden Markt von Geoinformationen und den steigenden
Bedarf an räumlichen Geometriedaten zu entwickeln und in der Folge auch eigenständig
zu vermarkten.


Semantic based Structuring of 3D technologies for their optimized use in cultural heritage documentation.

2015

RTF

43rd Conference of Computer Applications and Quantitative Methods in Archaeology, CAA 2015, Siena, Book of Abstracts.

Constant technological progress results in new possibilities to produce reliable and rich spatial data of cultural heritage objects: for instance, museums have started to digitize their collections, more and more archaeological excavations or features and entire CH buildings have been documented in 3D. It is now necessary to establish connections among different CH disciplines and several technical disciplines, and to work on collaborative projects.

Technicians and CH experts together evaluate the best technique for specific CH object documentation, implementation and use. This discussion arises from the knowledge gaps of each counterpart in respect to the other discipline. Projects such as Agora 3D (see below) clearly demonstrate the need for an evaluation of the different available techniques.

In order to make optimal use of these technological capabilities, it is important to identify and name the information required to best serve the reasoning processes in these application fields. Correspondingly it is necessary to know about the characteristics of digitization techniques producing the content adapted to the needs of the applications. Due to the considerable complexity of instruments and processes producing the data, it is helpful to have a clear structure which relates the capabilities of the instruments to the requirements of the applications.

The COST Action TD1201 “Colour and Space in Cultural Heritage (COSCH)” takes this need into account, aiming to enhance the understanding among these disciplines. We will focus on the already listed, structured and evaluated available 3D technologies. At the same time, experts in spectral and CH research started to list, structure, and evaluate their knowledge. These evaluations yield a structure of technologies, and ultimately the techniques and instruments using their characteristics. The understanding of these characteristics provides insights for their potential applications. The ontology knowledge model accessible through so-called “COSCHKR App” provides a knowledge structure. It benefits from the development of semantic technologies from the Semantic Web framework. Semantics, which provide meanings, are captured through the conceptual structure and are defined through the ontology. The overall aim of this ontology is the development of a software tool to enable a better understanding of data acquisition techniques and their support to optimally realize cultural heritage applications.